Integrated circuits (ICs), which often include millions or billions of semiconductor devices packaged within a single chip, are an underlying technology for modern computers and mobile electronic devices. These ICs and their underlying semiconductor devices have in large part been responsible for ushering in the modern communications age.
Semiconductor devices of ICs can be damaged by electrostatic discharge (ESD) events. Such ESD events can occur when static electricity is suddenly discharged from a body surface to a device. For example, during manufacturing or testing of ICs, an ESD event can occur between an engineer's finger and a semiconductor wafer on which a semiconductor device is located, causing a sudden in-rush of current or voltage to strike the semiconductor device. This sudden in-rush of current or voltage can catastrophically damage the device in a number of ways, such as blowing out a gate oxide or causing junction damage, for example. ESD protection circuits have been developed to protect against such ESD events.